Risk analysis procedure for woodframe roof sheathing panel debris impact to windows in hurricanes

Abstract

The assessment of losses during extreme events such as hurricanes is important for performance-based design of residential buildings. In this paper, a methodology for estimating the risk of debris impact, specifically roof sheathing panels, to windows as a result of hurricanes is introduced and applied to an illustrative example. The method is a combination of approaches on flat plate trajectories, numerical hurricane modeling, and statistical analysis of structural capacity. Within this methodology, one can estimate the risk of impact for one or more windows in a certain house group as a hurricane approaches and passes on a deterministic track as defined by the center of its eye. The impact risk is analyzed for the each hour making up the full hurricane duration rather than a single analysis using the blended (total) hurricane statistics. An illustration of the method is presented through a risk assessment of windborne debris impacts to windows in a house group located near the U.S. Gulf coast using a hurricane having the same track as hurricane Katrina in 2005. As a result, the probability of each window being hit by a roof sheathing panel (RSP) during each hour of the hurricane as well as during each hurricane is presented. The results quantify the risk from hour to hour during a hurricane and may serve to better orient houses in planned communities in hurricane prone regions as well as provide a better understanding of the interaction of hurricanes and structures.KEYWORDS: fragility, wind force, windborne debris, light-frame wood, hurrican